1. Field of the Invention
The present invention relates to a video signal processor used in a video signal playback system and, more particularly, to a circuit for processing a video signal digitally in order to compensate skew generated during high-speed playback of the video signal recorded onto a recording medium.
The instant application is based on Korean Patent Application No. 10178/1995, which is incorporated herein by reference for all purposes.
2. Discussion of Related Art
Currently, the most widely used video signal playback systems reproduce a video signal by recovering the video signal recorded onto a recording medium such as a magnetic recording tape (tape hereinafter). In general, the video signal recorded on the tape is recovered using from a magnetic head and then reproduced.
A general video signal processing system processes an analog video signal recovered from a head by analog processing, i.e., without change, or processes the video signal digitally in order to add separate functions, such functions often being referred to as trick play functions. For example, many video signal playback systems have a search function for viewing the information recorded on the tape at high speed.
In a video signal processing system for recording and reproducing a standard television video signal, when searching the analog video signal recorded onto the magnetic tape, the video signal of odd-occurring fields and the video signal of even-occurring fields, which field signals are recorded onto the magnetic recording tape while a rotary magnetic head rotates, are switched and scanned during reproduction. It will be appreciated that the standard television video signal includes sync signals that differ from each other by about 0.5 H, where H represents a horizontal period, in their synchronizing signals of even-occurring fields and odd-occurring fields. Skew develops if the video signal having different syncs is reproduced on a screen as it is without correction or compensation. Therefore, a conventional video signal playback system has a separate correction circuit for correcting the skew of 0.5 H in switching the field from even-occurring one to odd-occurring one. It will also be noted that during search operation, the noise generated due to lost synchronizing signals cannot be eliminated but is output as it is without noise compensation.
The present invention was motivated by a desire to avoid the problems associated with digital signal processing during a high speed search mode of operation.